A multifunction detector is disclosed which can be part of a system for locating an object within a field of regard, and for determining the range to the object, wherein the detector can include multiple mode functionality, such as a focal plane array (FPA) function and a read-out integrated circuit (ROIC) function.
Active imaging systems transmit energy into the environment and determine the presence of an object based on its reflection of the transmitted energy. Objects in the environment, such as optical and electro-optical targets, retro-reflect the transmitted energy. Retro-reflecting objects have a small reflectance angle, so that incident energy will be reflected in approximately the same direction from which it is received.
An exemplary system which uses retro-reflected energy from objects in the environment to detect or image the object is described in U.S. Pat. No. 5,408,541 (Sewell). This patent discloses using a laser to image retro-reflecting targets once the target has been detected with radar or a thermal imaging sensor.
U.S. Pat. No. 5,449,899 (Wilson) discloses a target detector which receives retro-reflected laser energy from an optical target. The Wilson patent discloses that when a target is detected, a separate range-finder with separate optics and detector can be pointed in a direction identified by the target detector to determine a range to the target.